Suppressors of ectopic UNC-5 growth cone steering identify eight genes involved in axon guidance in Caenorhabditis elegans.
The UNC-5 guidance receptor, in response to the UNC-6/netrin path cue, orients growing axons in a dorsal direction along the epidermis of Caenorhabditis elegans. When ectopically expressed in the touch neurons, which normally extend ventrally or longitudinally, UNC-5 is able to reorient their axons toward the dorsal side in an UNC-6-dependent manner. This forms the basis of a genetic screen to identify other mutations that, like unc-6 mutations, suppress unc-5-induced growth cone guidance. These mutations may identify new components required for pioneer axon guidance by unc-5. In this paper, we describe eight genes that are required for ectopic unc-5-induced growth cone steering. Mutations in four of these identify the previously known axon guidance genes unc-6, unc-40, unc-34, and unc-44 and mutations in four others identify the novel genes unc-129, seu-1, seu-2, and seu-3. Several of these mutations cause axon guidance defects similar to those found in unc-5 mutants. We propose that some or all of these genes may function in a developmentally important unc-5 signaling pathway.
Colavita
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Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada.
Culotti
J G
JG
D000818:Animals; D017487:Ankyrins / Q000502:physiology; D001369:Axons / Q000502:physiology*; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000502:physiology; D029742:Caenorhabditis elegans Proteins; D003599:Cytoskeleton / Q000502:physiology; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000502:physiology*; D008565:Membrane Proteins / Q000502:physiology*; D009154:Mutation; D011956:Receptors, Cell Surface; D017978:Receptors, Growth Factor / Q000502:physiology*
D017487:Ankyrins; D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D017978:Receptors, Growth Factor; C077588:UNC-5 protein, C elegans